The ability to simultaneously identify, quantitate, and analyze a large mixture of proteins between different functional states of cells and tissues is the ultimate goal of proteomics, and has the potential to identify signaling pathways and complex protein networks important in cancer biology. Because of the extremely diverse nature of protein expression through post-translational modifications (PTM) and RNA processing, and the wide dynamic range of expression, no single platform exists for quantitative differential analysis of global protein expression. This Shared Resource will therefore integrate three facilities and technological approaches to create a comprehensive proteomic effort by the BCM Cancer Center: 1) protein chemistry/ MS-based proteomics for identification and analysis (PTM-postranslational analysis) of individual proteins;2) expression of recombinant proteins in the baculovirus system and as monoconal antibodies (MAbs) from B-cell hybridomas, and 3) isolation, identification, and MS-based analysis of large protein complexes or "interactomes". The Protein Chemistry/MS-Based Proteomics component, under the direction of Dr. Richard Cook, has existed as a core facility at Baylor since 1989. The Recombinant Protein Expression components were started as new services in September of 2005 with the recruitment of Dr. Dean Edwards to Baylor. The interactome, or Pathway Discovery, component will be started as a new service under the direction of Dr. Jun Qin, a recognized leader in immuno-isolation and identification of regulatory protein complexes by MS. In addtion to directing the Baculovirus/MAb facility, Dr. Edwards will serve as the overall Leader of the Shared Resource to integrate the scientiific and administrative interactions among these three components. The Protein Chemistry/MS-Based Proteomic facility is a successful and cost effective resource that provided services for 67 Baylor investigators in 2005, of which 40% were Cancer Center members. The Baculovirus/MAb facility has only been in operation since September of 2005 and has already provided services for 11 investigators and has six projects scheduled. Global differential protein expression profiling will be developed as a future service by combining separation of proteins by two-dimensional gel electrophoresis or liquid chromatography coupled with high-through put MS. Additionally, we plan to develop multiplex immunoassay systems based on Luminex flow cytometric fluorescence bead technology.